David Susskind, TV's senior talk-show host, looks over today's medium

David Susskind, the host of television's first and longest-lived late-night talk show, is still talking after 24 years on the air. But he is also producing a lot of first-rate television drama and cinema.

Last Sunday Mr. Susskind entered his 25th year as host of what started in 1958 as ''Open End'' and four years later evolved into The David Susskind Show (Sundays on more than 100 stations in the US - check local listings for times).

Mr. Susskind recalls some of his favorite shows as I chat with him in his New York City skyscraper office. ''There was Bertrand Russell, Adlai Stevenson, and Richard Nixon; Bill Moyers, Gore Vidal, and Anthony Burgess. And of course there was the show we often repeat, Mel Brooks telling how to be a Jewish mother. We just did one which was especially poignant, ''I Hate Welfare,'' an interview with a reluctant welfare mother.''

Mr. Susskind would like to forget his famous interview with Nikita Khrushchev. ''That was traumatic because of all the newspaper hysteria against it and the pickets around my office. When we finally got on the air, I was inhibited by all the Sturm und Drang,'' he explains.

Are there characteristics which his best guests have in common?

''They have intellect, curiosity, eloquence, and perspective about themselves which manifests itself in a sense of humor.''

Doesn't Susskind share those qualities? He turns up the palms of his hands in a gesture of self-deprecation, something one does not often see in Mr. Susskind. ''Well, at least the sense of humor,'' he says. ''I feel that the ultimate redemption for all the everyday ugly things which happen is humor. It's what helps me get through the day.''

How does the grand master of talk shows rate other interviewers?

Johnny Carson: ''The fastest wit in the West. For 20 years he has been consistently funny, razor sharp, witty. Never funnier than when the unexpected happens.''

Dick Cavett: ''Clever but essentially a monologist. He looks at everybody as a foil so he can get in there and make a joke. Too cute, he's made his talent go a long way.''

David Letterman: ''He's caught the cutes from Dick Cavett. Huck Finn at midnight. Doesn't know how to interview.''

Phil Donahue: ''A good showman, he originated the choreographed talk show, might be staged by Jerome Robbins. He struts, hops around, gets the audience to play an important role.''

Barbara Walters: ''So good that people are jealous. Whether it's prime ministers or entertainment celebrities, she gets the biggest and does well with all of them.''

Gregory Jackson (invisible host of CBS Cable's ''Signature''): ''One of the best interviewers on the air because he listens, probes, after having done his homework.''

Mike Wallace: ''Excellent interviewer, although a little too abrasive even when it is not necessary. He is the prosecuting attorney, an intelligent prober who listens with all his might.''

Merv Griffin: ''Too worldly to be constantly playing the the role of a young innocent.''

Jack Paar: ''He really was the eccentric, erratic personality capable of doing just about anything on air. It made him exciting to watch.''

Steve Allen: ''A jack of all trades, Renaissance man in entertainment terms.''

TV morning news hosts: ''I listen to radio in the morning.''

How would Susskind rate Susskind as a talk-show host?

''I never watch my show. It makes me nervous. I use my hands tgo much. I'm never satisfied with the questions I ask. But I always do the requisite homework , whether it is economics or foreign policy. We are in our 25th year, so producer Jean Kennedy and I must be doing something right.''

Mr. Susskind is currently planning some unexpected directions with his program. ''This year we plan to do some shows with my wife, Joyce Davidson Susskind, as co-host. She has her own talk show in Canada.''

He is also involved in many other projects. There's a series for ABC based on the motion picture ''Lovers and Other Strangers'' which he also produced; a TV special based on the John Kobal biography of Rita Hayworth; and three motion pictures still in early development stages.

With all these projects in the works, is Mr. Susskind a satisfied man?

He shrugs, smiles the wry Susskind smile so familiar to talk-show buffs. ''Reasonably happy but never satisfied. How can I be satisfied when I have so many shows ready to go but nobody wants to do: a six-hour mini-series based on the Hiss-Chamberlain case, four nights of Gettysburg, biographical films about Robert E. Lee and Ulysses S. Grant? Some of the most fascinating material in the world.